Changes in the Antigenic Profiles during Coccoid Conversion of Helicobacterp ylori

Roe, Im Hwan; Sohn, So Hee; Kim, Jung Taik; Lee, Hak Sung; Lee, Jong Hwa; Shin, Hyeong Soon; Kim, Chang Kyu

Abstract

BACKGROUND/AIMS: There are several opinions whether the coccoid forms of Helicobacter pylori (H.pylori) are viable, infective or degenerative. The aims of this study were to induce coccoid conver-sion of H. pylori, to study antigenic evolutions during this conversion, and then, to elucidate the viability of coccoid forms.
METHODS
The antigenic evolution during coccoid conversion of H. pylori was studied by Western blotting using different sera from forty six patients who were H. pylori posi-tive. These sera were used to obtain the total antigens of the strain cultured for 2 days (100% rod) and for 15 days (>99% coccoid).
RESULTS
The antigenic profiles were not changed in 47.8% (22/46 cases) and were changed in 52.2% (24/46 cases) during coccoid conversion. Antigenic fractions disappeared during coccoid conversion were belonged to protein bands at 120 kDa (corresponding to CagA) and at 35 kDa (corresponding to porin or adhesin).
CONCLUSIONS
The result showed that coccoid forms of H. pylori retain the same cellular structures as rod form, and some of the antigens disappeared during coccoid conversion. Therefore, coccoid form might be viable, and represent one of the stages of biological cycle of H. pylori.